Note: Descriptions are shown in the official language in which they were submitted.
~ ~785~
-- 1 --
A METHOD AND AN ARRANGEMENT FOR THE ~ANUFACTURE OF PACKING
CONTAINERS
The present invention relates to a method for the feeding of
contents comprising liquid as well as solid particles in the manu-
facture of packing containers by repeated transverse flattening and
sealing of tubular packing material.
The invention also relates to an arrangement for the realisa-
tion of the method, this arrangement comprising devices for the
transverse flattening and sealing of a packing material tube exten-
ding substantially vertically and filled with contents as well as
elements extending into the tube for the feeding of contents to the
packing rnaterial tube.
Packing containers for e.g. milk or other liquid foodstuffs
are manufactured generally from laminated, flexible material which
comprises layers of paper and thermoplastics. A known packing con-
tainer is formed in that a laminate web, during its advance through
the packing machine, is successively converted to tubular shape by
the joining together of its two longitudinal edges and sealing them
to each other in a liquid-tight manner. The tube so formed is moved
substantially vertically downwards through the machine at the same
time as the contents are fed continuously via a -feeding pipe intro-
duced at the upper, open end of the tube which extends downwards
inside the tube. At the lower end of the tube the machine is provi-
ded with reciprocating processing jaws co-operating with one another
which compress the passing material tube at equal distances so that
transverse flattened zones are produced wherein the walls of the
material tube are sealed to one another in a liquid-tight manner.
The transverse sealing of the material tube takes place below the
contents level and the tube is thus converted to coherent, substan-
tially cushion-shaped packing containers completely filled with
contents. After the cushion-shaped packing containers have been
separated from one another by cutting through the transverse sealing
zones a final shaping process is carried out so that the packing
containers obtain the desired, e.g. parallelepipedic, shape.
~;25~7~5~
The packing contalners whlc'n are manufactured In th~
manner de~sri bed a~ove were usable up to now only for those
llquld contents whlch wholly lack, or In any case contaln only
very sm all, soll d p artlcles, e . g . f I nely dlstrl b u ted frult pulp
In Julce or the llke. Ihe reason for thls 1~ that any solld par-
tlcles posslbly present In the contents may on flattenlng of the
materlal tube below the llquld level end up between the materlal
layers whlch are to be sealed to each other and among other
thlngs cause leakages In the transverse seals at the top and bot-
tom of the paci~lng contalner. If contents In "solId~ form (thedeslgnatlon "solld" Is used In the descrlptlon and the clalms to
deslgnate contents in the form of Indlvldual, soild partlcles,
e.g. Iarger blts of frult, beans, pleces of asparagus or the ll~e
wlth or wlthout a liquld part) are to be packaged, the feedlng of
the contents has to take place ~Intermlttently and In rhythm wlth
the repeated transverse seallngs of the tube so as to prevent the
solld partlcles from dlsturbing the seallng operatlon. In other
words, the feedlng of a portlon of contents of the deslred volume
to each packlng contalner should be started as soon as the fIrst
(lower) transverse Joln of the packlng contalner has been formed
and be completed before the flattenlng and sealIng of the second
(upper) transverse Joln of the contalner of the package. In thls
manner It can be avolded that the solId partlcles of the contents
get between the materlal surfaces sealed together In the trans-
verse Jolns. The method Is comparatlvely slow, however, slnce ahlgh feed rate may cause the contents to spatter or be thrown
about durlng the fllllng so that In splte of the feedlng of the
contents In portlons the transverse Joln cannot be kept free from
solld partlcles. The method also Implles that the packlng con-
talners are not completely fllled, since the rlsk of Incluslonsof solld contents In the transverse Jolns would then be conslder-
ably Increased.
The present Inventlon provldes a method whlch makes It
posslble In the contlnuous manufacture of packlng contalners from
tubular packlng materlal to flll soild partlcles (blts of frult,
-- 2
~:578~i
etc.) togeth~r with liqu~d con-tents as well as individually,
without the disadvantages experienced hitherto.
The present invention also provides a method of the
aforementioned type which whilst retaining the high machine
speeds existing up to now makes it possible to fill solid con-
tents without increasing the risk of leaking packing containers.
According to the present invention there is provided a
method for the feeding of liquid contents and solid particles
during the manufacture of packing containers by repeated trans-
verse flattening and sealing of packing material in the form of a
tube, comprising, transversel~- flattening and sealing said pack-
ing material, feeding the solid particles to the tube in the form
of a metered quantity after said transverse flattening of the
packing material has been completed, feeding the liquid during a
period longer than feeding of the solid particles, said longer
feeding of solid particles has been ended, flushing wall surfaces
of the tube with the liquid, and subsequently transversely flat-
tening and sealing said packing material to form a packing con-
tainer having said liquid and solid particles therein.
Thus, according to the present invention the solid par-
ticles are fed to the tube in the form of a metered quantity as
soon as a transverse flattening has been completed whereas the
liquid is fed during a longer period which is ended only when the
feeding of solid particles has been ended.
In one embodiment of the method the feeding of liquid
is ended before the subsequent, transverse flattening has been
completed.
In another embodiment of the method the fe~ding of
liquid to a packing container is interrupted by the subsequent
transverse fl2ttening.
~ - 3
71~S5
In a further embodiment of the method the feeding of
liquid to the material tubP takes p:Lace con-tinuously at a con-
stant flow. Suitably the solid particles are fed centrally into
the tube, whereas the liquid is made to flow along the walls of
the tube. Preferably the solid particles are fed in a condition
partly mixed with liquid.
The present invention al~o provides an arrangement for
the realizat~on of the above-mentioned method, this arrangement
being simple and reliable in operation and designed so that it
can be used without major difficulties on known types of packing
machines.
In particular the present invention provides an
arrangement which is not sub;ect to the disadvantages of similar
arrangements known previously and which is uncomplicated and cap-
able of being washed and sterilized in a simple manner.
The present invention again provides an arrangement
which makes it possible to manufacture wholly filled as well as
partly filled packing containers.
According to the present invention therefore there is
provided an arrangement for the feeding of liquld contents con-
tents and solid particles during the manufacture of packing con-
tainers including devices for transverse flattening a~d sealing
of a packing material tube extending substantially vertically and
being filled with contents, as well as elements extending into
the tube for the feeding of contents to the packing material
tube, comprising, a first pipe for the feeding of liq~id and a
second pipe for the feeding of solid particles, the first and
second pipes defining the feeding elements, a spreader element
positioned at an opening end of the first pipe, the second pipe
being provided with a valve arrangement including a valve cone
located at a lower end of the second pipe and manoeuvrable bet-
ween an open and a shut position, in the shut posltion the valve
~j
~ - 3a -
~ ~S7 ~5S
cone rests against a valve seat formed at the lower end of the
pipe and the first pipe arranged to provide for delivery of the
liquid along wall surfaces of the tube so as to flush solid par-
ticles therefrom.
Thus, in accordance with t:he invention the feeding ele-
ments comprise a first pipe for the feeding of liquid and a sec-
ond plpe for the feedlng of solid particles, the second pipe
being provided with a valve arrangement.
2~
;~ , /, - 4 -
, ..;
12~7855
In one embodlment of the present Inventlon the second
plpe extends concentrically Inslde the flrst plpe. Sultably the
outlet openlng of the flrst plpe Is sltuated above the outlet
openlng of the second plpe. Deslrably the valve arrangement com-
prlses a va1ve cone located at the lower end of the plpe whlch Is
manoeuvrable between an open and a shut posltlon, In whlch It
rests agalnst the valve seat formed at the lower end of the plpe.
Sultably the valve cone Is located Inslde the plpe and Is formed
wlth a substantlally bobbln-shaped upper part. Preferably the
valve cone Is manoeuvrable by means of a valve splndle extendlng
concentrlcally Inslde the second plpe.
In a further embodIment of the Inven-tlon the spreader
element Is arranged at the openlng end of the fIrst pl?e. Sult-
ably a thlrd plpe for the feedlng of a gaseous medlum extends
Inslde the tube. Deslrably all the plpes open In a lower part of
the tube whlch is delImlted from the upper, open part of the tube
as well as from the surroundlng alr by means of a sealIng devlce.
Preferably the second plpe at the upper, open end of the materlal
tube Is connected to a meterlng pump. Sultably the flrst plpe at
Its upper part extendlng through the open end of the materlal
tube Is connected vla a constant flow valve to a reservolr for
the llquld contents.
The method and the arrangement In accordance wlth the
Inventlon present many advantages in that they ellmlnate the dls-
advantages of prevlous constructlons and methods and make It pos-
slble to make use of known prlnclples of package formatlon for
the manufacture of packlng contalners whlch are wholly or partly
fllled wlth contents comprlslng a larger or smaller, accurately
metered portlon of solId partlcles. The volume of contents In
each Indlvldual packlng contalner can be regulated wlth great
accuracy, and flulds wlth solld partlcles of dlverse klnd can be
fllled. The method and the deslgn of the arrangement elImlnate
the rlsk of partlcles of contents attachlng themselves between
the materlal surfaces pressed to each other In transverse lolns
~ - 4a -
, . .
,
:i~257855
and thus ensure completely tlght transverse seals which make It
posslble to flll In aseptlc as well aS non-aseptlc manufacture
any types of contents whlch occur In practlce In the foodstuffs
branch.
A preferred embodiment of ~he method as well as of the
arrangement In accordance with the Invention wlll now be des-
crlbed In more detall wlth speclal reference to the accompanylng
schematlc drawlngs, In whlch:-
F I 9 . 1 shows In princlple the conversion of a weblli<epacking materlal to I ndlvldua I pack I ng conta I ners In a packlng
machlne;
Flg. 2 shows partly In sectlon and on a larger scale
the converslon Of a packlng materlal tube to Indivldual packlng
contalners In accordance wlth a preferred embodlment of the
method In accordance wlth the Inventlon; and
Flg. 3 shows on a larger scale and partly In sectlon
the lower part of the packing materlal tube In accordance wlth
Flg. 2.
The packlng machlne Indlcated In Flg. 1 Is of a maln
type known earller whlch converts weblIke packlng materlal to
Indlvldual packlng contalners. The packlng materlal Is a laml-
nate whlch usually comprlses a central carrler layer of paper
whlch Is covered on both sldes wlth thln, llquld-tlght layers Of
thermoplastlc materlal, e.g. polythlene. The packlng lamlnated
Is provlded wlth crease llnes to
- 4b -
855
facilitate folding and conversion to finished packing containers
and is supplied to the packing machine 1 in the form of a roll 2
which is supported so that it can rotate in the magazine of the
packing machine. From the magazine the packing material web 3
moves via a number of guide rollers 4 up to the upper part of the
machine where it passes over a deflection roller 5, thereafter to
continue substantially vertically downwards through the packing
machine.
With the help of various folding and forming elements 6, 7
arranged along the path of movement of the material web, the
packing material web 3 during its movement downwards through the
machine is converted successively to tubular form in that its two
longitudinal edges are guided towards each other and sea1ed together
so that a material tube 8 with a longitudinal liquid-tight seal is
produced. The sealing together of the two longitudinal edges takes
place with the help of a supply of heat by means of a sealing unit
9 of the hot-air type whereby the parts of the thermoplastic layer
situated at the edges are made to melt. Thereafter the two longitu-
dinal edges are pressed together with simultaneous cooling which
means that the thermoplastic layers are joined to one another so
that the desired, wholly liquid-tight join is obtained.
The contents are then conducted to the lower end of the packing
material tube 8 so formed via a feed pipe 10, 11 which extends in
through the upper, open end of the packing material tube 8. The feed
pipe then runs substantially concentrically downwards through the
packing material tube and opens at a little distance above the
lower end of the same which will be explained in more detail in the
following.
At some distance below the feed pipe 10, 11 forming and sealing
jaws 12, 13 (fig. 2) are arranged on either side of the packing
material tube 8 which are adapted so as to process the packing
material tube 8 in pairs between themselves. For the sake of clarity
only one set of forming and sealing jaws respectively is shown in
the figures, but in practice there are usually a further number of
jaws which alternatingly process the packing material tube.
~57855
The sealing jaws 13 are moved continuously to and fro in the
direction towards and away from each other respectively so as to
compress and seal the packing material tube along transverse
sealing zones. At the same time the sealing jaws 13 are moved to
and fro in vertical direction so that when they are in the upper
end position they are moved towards one another and compress and
retain the packing material tube. In the subsequent movement down-
wards through the packing machine the walls of the packing material
tube are compressed and welded to each other, the material tube
being advanced at the same time over a distance which corresponds
to the length of one packing container blank. During the displace-
ment downwards the two forming jaws 12 are swung towards each other
so that the part of the packing material tube 8 which is located
directly above the sealing jaws 13 is partly compressed and formed
to the desired shape, in this case substantially cushion shape with
a rectangular cross-section. When the sealing jaws 13 have reached
their lower position the forming jaws 12 are swung out again to the
position shown in fig. 2 at the same time as the material tube 8 is
severed by a transverse cut through the zone compressed by the
sealing jaws. As a result a packing container 14 formed previously
will be detached from the packing material tube. After the sealing
jaws 13 have been moved away again from each other the packing con-
tainer 14 is passed with the help of a conveyor (not shown) for
continued processing and final shaping so that a packing container
of the required shape (in this case parallelepipedic) is produced.
As mentioned earlier, the desired contents are fed to the lower
end of the packing material tube 8 via the feed pipe 10, 11. On
filling of contents which contain liquid as well as solid particles
the feed pipe is divided into two separate ducts or filling pipes
10 and 11 respectively, the liquid freed from particles being fed
via one filling pipe 10 whereas the solid contents (preferably mixed
with a certain amount of liquid) are fed via the second filling
pipe 11. The two filling pipes 10, 11, as mentioned earlier, in the
form of the combined feed pipe 10, 11, extend partly through the
upper open end of the packing material tube 8, whereafter (see in
~25'7855
particular fig. 2) they run substantially vertically downwards. The
vertical parts of the pipes may run parallel alongside one another
or be combined, e.g. in that the second pipe extends concentrically
inside the first pipe, which not only saves space but also facili-
tates washing and sterilising, since narrow and not readily acces-
sible spaces and recesses are thereby avoided.
The first filling pipe 10 intended for liquid is connected at
its upper end via a valve 15 to a tank or reservoir 16 for the
liquid contents. The valve 15 may be designed as a constant flow
valve, that is to say a valve which beside its shutoff action is
also adjustable for a constant flow of a desired quantity of liquid
per unit of time.
The second filling pipe 11, like the first filling pie 10,
extends out of the upper open end of the packing material tube 8
where the second filling pipe is connected to a metering pump 17
and a tank or reservoir 18 for the solid contents which, in order
to make possible the filling, are mixed with a certain portion of
liquid contents, e.g. of the same type as the contents present in
tank 16. The metering pump 17 is constituted preferably of a piston
pump which at each stroke delivers a predetermined quantity of con-
tents from the tank to the filling pipe.
At the lower end of the second filling pipe 11 a valve arrange-
ment 19 is present which is best illustrated in fig. 3, showing the
lower end of the material tube and adjoining elements on a slightly
larger scale. More particularly, the valve arrangement 19 comprises
a valve cone 20 located at the lower end of the second filling
pipe 11 which by means of a valve spindle 21 extending concentri-
cally inside the pipe is manoeuvrable from the outside between the
upper open position and a lower shut position, in which it rests
against a valve seat 22 formed at the lower end of the pipe 11. To
facilitate the flow of contents in the valve cone 20 the latter is
designed so that it has an upper bobbin-shaped part, at the same
time as the lower part of the filling pipe 11, where the valve cone
is situated has a widened substantially pear-shaped part, at the
bottom end of which is situated the valve seat 22.
~257855
As mentioned previously, the second filling pipe 11 extends
preferably concentrically in the first filling pipe 10. The first
filling pipe 10 is a little shorter than the second and the outlet
opening 23 of the first filling pipe 10 is situated therefore at a
little distance above the outlet opening 24 of the second pipe.
Hence the outlet opening 23 of the first pipe 10 will be situated
at a little distance above the widened lower part of the filling
pipe 11. Between the said widened pipe section and the ou-tlet ope-
ning 23 there is a spreader element 25 which is situated directly
below the outlet opening 23 and is designed as a collar or bell
which, when liquid flows out of the outlet opening, disperses the
same outwards in the direction of the inner wall surfaces of the
contents tube 8 which will be explained in greater detail in the
following. It is possible for the upper part of the widened section
of the filling pipe 11 to be so designed and placed in relation to
the outlet opening 23 that it serves as a spreader element and thus
replaces the separate spreader element 25 shown in fig. 3.
The filling pipe 10 as well as the filling pipe 11 open into
a lower part of the packing material tube 8 at some distance above
the place where during operation the forming and sealing jaws 12,
13 process and press together the material tube.
This lower part of the tube is delimited from the upper open
part of the tube with the help of a sealing device 26 which compri-
ses a circular sealing lip 27 of flexible material, e.g. rubber or
plastics, restin~ against the inner surface of the material tube.
The sealing device 26 is carried by the first filling pipe 10 and
thus adjoins the outer surface of the same in a sealing manner. A
third pipe 28 also extends through the sealing device 26 for the
feed of gaseous medium to the lower end of the material tube closed
by means of the sealing device 26. The pipe 28, like the two other
filling pipes 10, 11, extends out through the open, upper end of
the tube where the pipe is connected via a valve 29 to a pressure
tank 30 which contains sterile air at a predetermined pressure. The
tank 30 is connected to a compressed air supply, not shown.
When the packing machine with the arrangement in accordance
~L~2 S 7 ~35 S
with the invention is in operation, the packing material web is
advanced from the roll 3 via a number of deflection and guide
rollers 4, 5 to the upper part of the packing machine, whereafter
it is moved substantially vertically downwards through the machine.
During the movement of the material web 3 downwards through the
machine a successive conversion of the material web to tubular
shape is taking place in that its two longitudinal edges are acted
upon in direction towards each other by folding and forming
elements 6, 7 arranged in the path of movement of the material web.
When the material web 3 has been folded to such an extent that the
two longitudinal edges overlap one another, they pass the sealing
unit 9 wherein the thin thermoplastic outer layers of the material
web are subjected to a current of hot air which heats the thermo-
plastics to melting temperature. Then the two edges are pressed
against each other whilst being cooled so that the thermoplastic
layers are caused to fuse together and a packing material tube with
a liquid-tight longitudinal join is obtained. During its continued
movement downwards through the machine the packing material tube is
filled with contents via the feed pipe 10, 11, whereafter the
material tube is converted with the help of forming and sealing jaws
12, 13 through repeated transverse flattening and forming to substan-
tially cushion-shaped packing container blanks. At the same time as
the sealing jaws 13 flatten the packing material tube between them-
selves, heat is supplied so that the thermoplastic layers situated
on the inner surfaces of the packing material tube melt and are
sealed to one another. As a result a liquid-tight seal is produced
which either has a relatively large width or is divided into parallel
sealing areas between which the material tube is then cut so that the
packing container formed can be detached from the material tube. At
the same time the material tube acquires a liquid-tight seal at its
bottom end and the process can be repeated for the manufacture of
further packing containers.
When the packing material web 3 has passed the sealing unit 9
and thus has been converted to the liquid-tight packing material
tube 8, it passes the sealing device 26 whose sealing lip 27 rests
12~37~355
- 10 -
in a flexible manner against the inner surface of the packing
material tube. As a result of this a lower separate chamber is
formed into which open both filling pipes 10, 11 as well as the
feed pipe 28 for sterile air. The said chamber is pressurised via
the feed pipe with sterile air of the desired pressure which is fed
continuously in rhythm with the consumption of air caused by the
fact that each finished package comprises a certain quantity of
air so as to form a so-called headspace. In the course of the
continuous feeding of air under pressure via the feed pipe 28 a
certain pressure in the lower closed end of the packing material
tube is maintained. This pressure is required to make possible the
shaping of the tube and prevent the material tube from being
wrinkled together in an unchecked manner when the shaping jaws 12
compress it so as to impart to the same a substantially square
cross-section.
The two cooperating sealing jaws 13, as mentioned previously,
on the one hand move towards and away from each other to make
possible the repeated, transverse flattening of the packing
material tube, on the other hand move vertically upwards and down-
wards in working and return strokes to advance the packing materialtube and detach suitable lengths of the same for the manufacture of
individual packing containers. The feed of contents takes place in
rhythm with the movements of the sealing jaws and, more particu-
larly, the solid particles are fed in the form of a metered quantity
as soon as the sealing jaws have completed a transverse flattening
and the packing material tube consequently is sealed off from the
newly formed packing container. The liquid contents are fed during
a longer period which is ended only when the feed of solid particles
has been ended. To avoid any jamming of solid particles between the
material layers pressed together by the sealing jaws it is of great
importance that the part of contents which contains solid particles
is not fed in such a way that it reaches the lower end of the tube
before the pressing together of the tube walls with the help of the
sealing jaws 13 has been completed. The sealing work itself, that
is to say the heating and sealing together of the layers of thermo-
~2~57855
plastic material in the transverse, flattened region of the tube,however, does not have to be completed or even have been started
when the solid particles reach the lower end of the tube, since
the pressing together by itself ensures that the lower end of the
tube has sufficient tightness to prevent any particles from reaching
the actual sealing region. Consequently the feeding of solid
particles may commence as early as possible during the working
cycle, which is of considerable importance for the working rate
of the machine, since the time available for the filling of each
packing container is very limited.
The feed of the solid contents is facilitated, as mentioned
previously, in that the particles of contents are mixed up with
liquid, and the mixture is pumped with the help of the metering
pump 17 via the second filling pipe 11 to the lPwer end of the
packing material tube. The metering pump 17 is preferably of the
piston type and is synchronised with the movement of the sealing
jaws 13 so that the feeding of the desired quantity takes place at
the correct juncture in accordance with the above reasoning. The
valve arrangement 19 situated at the lower end of the second filling
pipe too is manoeuvred in rhythm with the movement of the sealing
jaws 13 and ensures that the lower end of the filling pipe 11 is
open only during the correct period in relation to the movement of
the jaws and the working stroke of the pump 17. The valve 19 is shut
preferably only after the pump 17 has commenced its return stroke
so that during a limited period a certain return suction in the
filling pipe 11 is created. This helps to ensure that no after-
dripping in any form from the filling pipe takes place which is of
great importance since otherwise the surfaces, which afterwards are
to be pressed together for the formation of transverse sealing
zones, may be contaminated by solid particles of the contents.
To eliminate further the risk of contaminations by solid
particles on the surfaces which are to be sealed, use is made of
the liquid contents which are fed via the first filling pipe 10 in
order to flush clean the wall surfaces of the packing material tube.
More particularly, the liquid contents, as they flow out through the
~257~35~
- 12 -
outlet opening 23 at the lower end of the first filling pipe 10,
are directed in such a way with the help of the spreader element 25
that they flow along the inner wall surface of the tube. The feed
of the liquid contents may be continuous and occur at a uniForm
speed which is regulated with the help of the constant flow valve
15. Through correct adaptation of the outflowing quantity of liquid
per unit of time the feed of the liquid contents portions to each
individual package can be controlled simply through movement of the
sealing jaws 13. The feed of liquid to each individual package will
thus be limited simply in that the jaws 13 flatten the material tube
and so interrupt the inflow to the actual package. If desired it is
also possible, of course, to introduce a shutoff valve controlled
in rhythm with the sealing jaws 13 into the filling pipe 10 so that
the feed of liquid can be interrupted already before the transverse
flattening of the packing material tube 8 has been completed. This
method can be particularly appropriate in the filling of partially
filled packing containers with contents whose solid particles are
relatively small and mobile, since any risk of the inflowing liquid
contents "swirling up" the solid particles to the region intended
for the upper transverse sealing is thereby eliminated. However, the
flow of liquid contents along the inner wall surface of the material
tube has proved in practice to provide good safety that particles
from the inside of the material tube will not be present on the
surface when the flattening takes place, even if contents particles
were to contaminate the surface of the packing material in spite of
the feeding being central and synchronised with the jaw movements.
By the arrangement and method in accordance with the invention
it has been found possible in practical experiments to fill a packing
container with contents in the desired quantity and the desired
ratio between the solid and liquid parts with great accuracy. Whilst
the filling can take place at an unexpectedly high speed, the risk
of inclusion of particles of goods in the transverse seals has been
eliminated so that the packing containers produced show good tight-
ness.
